Valves are used in various environments such as vacuum and fluid environments to isolate two regions from one another. Valves may also be used to control the flow of fluids and substances, and in some cases, harmful or corrosive substances from one region to another. Valves may be used in various types of processing systems such as in semiconductor fabrication processing where a vacuum condition facilitates treatment of a workpiece. One type of semiconductor fabrication processing occurs in an ion implanter that generates an ion beam to treat a workpiece such as a semiconductor wafer. Such ion implanters have different chambers to generate and control the ion beam and a valve may be used to connect various vacuum chambers within the ion implanter.
A valve may be positioned between an ion source and a downstream chamber of an ion implanter such as a mass analysis chamber. The valve facilitates maintenance or changing of the ion source, since other portions of the ion implanter may be maintained under high vacuum conditions while the ion source may be vented to atmospheric conditions. Once the ion source has been maintained or changed, the valve may be reopened to allow an ion beam extracted from the ion source to pass there through. However, when the valve is open, deposits and debris originating from the ion source may form on components of the valve such as the gate causing damage to an extent that the valve cannot properly seal the ion source from other portions of the ion implanter.
One conventional apparatus for protecting the valve requires enough physical space between each region such as the ion source and a downstream mass analysis region for a valve body to be positioned. During a closed position, the gate for the valve is positioned in the valve body. During an open position, the gate is retracted into a housing having a cover that then closes to protect the gate. Although this is effective for protecting the gate from harmful deposition, this type of valve protection is ineffective in protecting the sealing surface of the valve and requires physical space between two regions that may not be available. In addition, it also requires additional components and costs for the protective gate housing and cover.
Accordingly, there is a need in the art for a valve that overcomes the above-described inadequacies and shortcomings.